Water–formaldehyde–hydrogen sulfide system. II. Formation and growth of thiomethylenic chains.

Abstract

SynopsisA linear polymer with a high melting point is obtained from the water-formaldehydehydrogen sulfide system in the presence of sulfuric acid. This polymer is substantially formed by a polythiomethylene chain with a few oxymethylene units. Its formation involves a topochemical reaction of the mercaptomethanol present in solution on the first separation solid of the system. On heating, the polymer loses oxymethylene units; in the same way, the first solid product separated from the system loses formaldehyde and undergoes a morphological and chemical transformation to polythiomethylene.

Nucleophilic substitution reactions of dihalomethanes with hydrogen sulfide species

“…Melting points reported for poly(thiomethylene) vary widely, presumably reflecting differences in polymer chain length related to different methods of preparation: ca. 80,123-124,160-205,175-176, 220-230, 220-245, 220-248, 220-255, and 245-260 °C have all been reported (56,(58)(59)(60)(61)(62)(63).…”

“…Early studies conducted in Germany in the late 1800s (50-52) indicated that CH2I2 reacts with Na2S in aqueous solution or NaHS in alcohol solution to form the cyclic thioformaldehyde trimer 1,3,5-trithiane [mp 220 °C (53)]: ch2-s sz ch2 \h2V 1,3,5-trithiane This also represents the major product of the reaction of H2S with formaldehyde in aqueous solution under acidic conditions (54). Other polymers identified from the reaction of dihalomethanes or formaldehyde with hydrogen sulfide species include the linear polymer poly(thiomethylene) [HS(CH2S)"H, n > 1] and minor amounts of the cyclic thioformaldehyde tetramer 1,3,5,7-tetrathiocane [mp 48-49 °C (55,56)] and pentamer 1,3,5,7,9-pentathiacyclodecane [mp 120-123 °C (56, 57)], as well as copolymers of poly(oxymethylene) /poly(thiomethylene) (58,59).…”

“…Unlike the cyclic thioformaldehyde polymers, which are all reported as soluble in benzene, poly(thiomethylene) is regarded as insoluble in common organic solvents at temperatures below ~200 °C (58), although Gipstein et al (60) noted it is soluble in " -bromonaphthalene and a solvent mixture of tetramethylene sulfone and a-chloronaphthalene above 210 °C" (but not at lower temperatures), and Lai (61) reported it to be soluble in "ophenylphenol and mixed tetrachlorobiphenyl" (Arochlor 1254) at ~230 °C. Melting points reported for poly(thiomethylene) vary widely, presumably reflecting differences in polymer chain length related to different methods of preparation: ca.…”

Thiol‐Aldehyde Polycondensation for Bio‐based Adaptable and Degradable Phenolic Polymers

“…Our attention is drawn to polythiomethylene, which is prepared from hydrogensulfide and formaldehyde (Scheme 1b). [31] Hydrogen sulfide and formaldehyde can be respectively viewed as the shortest di-thiol compound and the simplest aldehyde. Mechanistically, polythiomethylene is a product from thiol-aldehyde polycondensation.…”